Table 1

Demographic, clinical, and biomarker characteristics stratified by cancer status or membership in the training and test sets

FactorOverall (n = 163)Cancer (n = 78)No cancer (n = 85)P*Train (n = 76)Test (n = 62)P*
Age58.1 ± 14.364.5 ± 9.652.3 ± 15.4<0.00157.3 ± 14.057.5 ± 15.30.91
Male122/163 (74.8)60/78 (76.9)62/85 (72.9)0.5959/76 (77.6)42/62 (67.7)0.25
Caucasian110/163 (67.5)67/78 (85.9)43/85 (50.6)<0.00152/76 (68.4)36/62 (58.1)0.22
Smoked within 10 y130/163 (79.8)60/78 (76.9)70/85 (82.4)0.4462/76 (81.6)47/62 (75.8)0.53
Pack-years44.9 ± 32.054.9 ± 26.835.7 ± 33.7<0.00145.8 ± 30.239.9 ± 35.40.3
Diagnostic bronchoscopy45/163 (27.6)40/78 (51.3)5/85 (5.9)<0.00120/76 (26.3)0/62 (0)<0.001
Cancer78/163 (47.9)78/78 (100.0)0/85 (0.0)<0.00140/76 (52.6)17/62 (27.4)0.003
Lymphadenopathy43/163 (26.4)36/78 (46.2)7/85 (8.2)<0.00117/76 (22.4)10/62 (16.1)0.4
Hemoptysis15/163 (9.2)6/78 (7.7)9/85 (10.6)0.610/76 (13.2)2/62 (3.2)0.07
Mass size >3 cm48/163 (29.4)43/78 (55.1)5/85 (5.9)<0.00124/76 (31.6)10/62 (16.1)0.047
Biomarker−0.35 ± 8.934.65 ± 7.04−4.94 ± 7.98<0.0010.34 ± 8.97−2.72 ± 9.120.05

NOTE: Data are means ± SDs for continuous variables and proportions with percentages for dichotomous variables.

  • *P values are for the comparison of patients with and without cancer and for the comparison of the training and test sets. Two-sample t tests with unequal variances were used for continuous variables; Fisher's exact test was used for dichotomous variables.